多胺对大鼠肝脏异亮氨酰 - tRNA合成酶形成异亮氨酰 - tRNA的影响。

Effect of polyamines on isoleucyl-tRNA formation by rat-liver isoleucyl-tRNA synthetase.

作者信息

Igarashi K, Eguchi K, Tanaka M, Hirose S

出版信息

Eur J Biochem. 1978 Jan 2;82(1):301-7. doi: 10.1111/j.1432-1033.1978.tb12024.x.

DOI:10.1111/j.1432-1033.1978.tb12024.x

Abstract

The effect of polyamines on rat-liver isoelucyl-tRNA formation was studied using isoleucyl-tRNA synthetase purified by column chromatography successively on Sephadex G-200, DEAE-Sephadex A-25, and tRNA-Sepharose 4B. In the presence of 50 mMK+, isoleucyl-tRNA formation was inhibited markedly by 1.5 mM or higher concentrations of Mg2+. However, the addition of spermine to the reaction mixture prevented the inhibitory effect of Mg2+. In the presence of 200 mMK+, the addition of spermine to the reaction mixture stimulated isoleucyl-tRNA formation in the presence of Mg2+ concentrations from 0 to 5 mM. Although the effective concentration was different, spermidine exhibited a similar stimulative effect. The effective concentration of spermine required for stimulation was higher when larger amounts of tRNA were used. The stimulatory effect of isoleucyl-tRNA formation by polyamines was shown to reflect on polypeptide synthesis. When formaldehyde-treated poly(A,U) was used as messenger RNA, polypeptide synthesis from amino acids was stimulated by polyamines, but that from aminoacyl-tRNAs was not stimulated by polyamines.

摘要

使用先后经Sephadex G - 200、DEAE - Sephadex A - 25和tRNA - Sepharose 4B柱层析纯化的异亮氨酰 - tRNA合成酶，研究了多胺对大鼠肝脏异亮氨酰 - tRNA形成的影响。在50 mM K⁺存在的情况下，1.5 mM或更高浓度的Mg²⁺会显著抑制异亮氨酰 - tRNA的形成。然而，向反应混合物中添加精胺可防止Mg²⁺的抑制作用。在200 mM K⁺存在的情况下，向反应混合物中添加精胺会在0至5 mM的Mg²⁺浓度下刺激异亮氨酰 - tRNA的形成。尽管有效浓度不同，但亚精胺也表现出类似的刺激作用。当使用较大量的tRNA时，刺激所需的精胺有效浓度更高。多胺对异亮氨酰 - tRNA形成的刺激作用被证明反映在多肽合成上。当用甲醛处理的聚（A，U）作为信使RNA时，多胺会刺激从氨基酸合成多肽，但不会刺激从氨酰 - tRNA合成多肽。